Materials Literature
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The one-step synthesis of amino-polyether tri-tert-butyl ester monomer 2, by condensation of TRIS with tert-butyl acrylate, is reported. The nitrogen of the monomer can be protected with a Cbz group; subsequent removal of the tert-butyl esters with formic acid affords a triacid that is coupled to three monomers to aff…
The new tris( tert -butoxy)siloxy complexes of aluminum, Al[OSi(O t Bu) 3 ] 3 (THF) ( 1 ), Al[OSi(O t Bu) 3 ] 3 (HO i Pr)·0.5[Al(O i Pr) 3 ] 4 ( 2 ), and [( i PrO) 2 AlOSi(O t Bu) 3 ] 2 ( 3 ), were synthesized. Compounds 2 and 3 were structurally characterized by single-crystal X-ray crystallography. Thermolysis of a…
We have investigated the possibility of using carbon nanotubes as flexible, mobile electrical probes able to electrically contact nanometre-scaled objects. Configurations with metal electrodes evaporated on top of multi-, few- and single-wall carbon nanotubes have been studied. Scanning probe manipulation was used to…
Monochromatic UV light in the spectral interval between 4.0 and 5.5 eV is used in order to selectively excite 3- and 4-coordinated oxygen anion sites on the surface of MgO nanoparticles exposed to O2 gas. As a result, two different paramagnetic O− surface species and also ozonide anions O3− are observed by electron pa…
Texture measurement with short-wave X-ray synchrotron radiation in the range of λ ≃ 0.1 Å is described. The measurements were carried out with the multipurpose diffraction instrument at the high-field wiggler, high-energy beamline BW5 at HASYLAB. The instrument was equipped with an on-line image-plate area detector fo…
Abstract The graft copolymerization of 50/50 (w/w) styrene/methyl methacrylate mixtures onto natural rubber seed latex were carried out by using cumene hydroperoxide/sodium formaldehyde sulfoxylate dihydrate/EDTA‐chelated Fe 2+ as a redox initiator. The effects of the process factors such as the amount of initiator, e…
Novel heterogeneous compounds of methylrhenium trioxide (MTO) were prepared with poly(4-vinylpyridine) and polystyrene as polymeric supports. The wide-angle X-ray diffraction (WAXS.) analysis, performed by the application of the difference method, showed, in a representative case of the poly(4-vinylpyridine)/MTO deriv…
Calculations based on density functional theory (DFT) were performed on various structural isomers of methyl silsesquioxanes, [MeSiO 3/2 ] n where n = 4, 6, 8, 10, 12, 14, and 16, to study their structural and electronic properties. The calculated results find the stability of methyl silsesquioxanes, except [MeSiO 3/2…
A novel method to deconvolute the instrumental aberration functions from the experimental powder X-ray data has been developed. The method is based on the combination of scale transformation, interpolation of data and fast Fourier transformation. The effects of axial divergence, flat specimen, sample transparency and…
Abstract The gelatinization and extrusion processes of corn starch were studied. Differential scanning calorimetry was used to determine the gelatinization temperature as a function of the water content. Plasticized corn starch was processed in single‐ and twin‐screw extruders to produce thermoplastic materials. The m…
A novel and efficient method for the production of enantiomericaly pure R-3-hydroxyalkanoic acids and R-3-hydroxyalkanoic acid methylesters was developed. The described method is based on hydrolysis of poly(hydroxyalkanoate) copolymers synthesized by Pseudomonas putida. The polymer was isolated via solvent recovery an…
A high-performance neutron diffractometer for biological crystallography (BIX-3) has been constructed at JRR-3M in the Japan Atomic Energy Research Institute (JAERI) in order to determine the hydrogen-atom positions in biological macromolecules. It uses several recent technical innovations, such as a neutron imaging p…
Two novel complexes trans -[Fe(MBPT) 2 (NCS) 2 ] ( 1 ) and cis -[Fe(mMBPT) 2 (NCS) 2 ] ( 2 ) have been synthesized and their structure characterized at 293 K by single-crystal X-ray crystallography [MBPT (or mMBPT) = 4- p( or m) -methylphenyl-3,5-bis(pyridin-2-yl)-1,2,4-triazole]. Complexes 1 and 2 are isomers, and 1…
A theoretical study is presented of the ring-opening polymerization (ROP) mechanism of 1,5-dioxepan-2-one (DXO) and glycolide with Sn(II) and Al(III) alkoxide initiators (SnMe 3 MeO, SnMe 2 (MeO) 2, and AlMe 2 MeO). The B3LYP density functional method has been used to perform the quantum chemical calculations. A coord…
Polyaniline thin films were prepared by ac plasma polymerization technique. Capacitance, dielectric loss, dielectric constant and ac conductivity of these films were investigated in the frequency range from 100 Hz to 1 MHz and in the temperature range from 300 to 373 K. Capacitance and dielectric loss decreased with f…
It is known that the determination of the equilibrium melting temperatures of polymers which show recrystallization during heating is a difficult problem. This is mainly due to the difficulty encountered in determining the melting temperature of the initial lamellae which exist before recrystallization takes place. We…
Mesoporous silica films with uniaxially aligned large-sized mesochannels were prepared using nonionic alkyl poly(ethylene oxide) surfactants and a rubbing-treated polyimide coating. Although the increment of the pore size was small as long as conventional alkylammonium surfactants were used, the use of nonionic surfac…
The results of density functional theory potential surface investigations are presented for small ZnS, ZnSe, CdS, and CdSe clusters, up to the heptamer. Clusters of CdSe are investigated further by geometry optimizations of larger crystal structure sections with up to 198 atoms that correspond to the wurtzite modifica…
Cuprite (Cu 2 O) nanowires with diameter of 25−100 nm were electrodeposited from anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate reverse hexagonal liquid crystalline phase. The nanowires can be grown to up to tens of micrometers in length by simply changing the electrodeposition time. Resistivity measuremen…
para-Hydroxybenzoate hydroxylase catalyzes a two-step reaction that demands precise control of solvent access to the catalytic site. The first step of the reaction, reduction of flavin by NADPH, requires access to solvent. The second step, oxygenation of reduced flavin to a flavin C4a-hydroperoxide that transfers the…